The invention relates to marine drives, and more particularly to an apparatus and method for preventing ice build-up in the carburetor of a marine drive.
Carburetor icing is a problem that may occur when a marine drive is operated in cooler ambient temperatures combined with high moisture content in the air which may be the result of high humidity or the splash and mist of operating the marine drive in water. When the carburetor mixes fuel and air under such conditions, ice may form over, or in, the small holes which make up the idle and off-idle circuits of the carburetor. Carburetor icing can occur in ambient temperatures above the freezing point of water due to the cooling effects of the carburetor venturi and the evaporative cooling effect of the fuel in the carburetor. The formation of ice particles in and around the carburetor circuit holes results in a malfunction of the air/fuel delivery circuit of the carburetor, thereby causing poor performance, and in severe cases, stalling of the engine.
The addition of a water disbursing additive to the fuel is ineffective in preventing carburetor icing in marine drives because the source of the water is in the air that the marine drive operates-not the fuel. Since a marine drive inherently operates under high moisture conditions, operating in cooler ambient temperatures, or when an unexpected drop in temperature occurs, could strand an operator in the middle of a body of water. Further, once carburetor icing occurs, the operator has very limited options available because the presence of a flammable fuel in the carburetor limits the application of heat sources to thaw the carburetor icing. Therefore, a method and apparatus to prevent carburetor icing is highly desirable in marine drives.